Finding the Fourth Proportional to 2,081.20, 3,120.59 and 985.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,081.20 : 3,120.59 = 985.55 : x
2. Step 2: Convert to fraction form
   2,081.20/3,120.59 = 985.55/x
3. Step 3: Cross multiply
   2,081.20x = 3,120.59 × 985.55
4. Step 4: Simplify right side
   2,081.20x = 3,075,492.55
5. Step 5: Solve for x
   x = 3,075,492.55/2,081.20
6. Step 6: Final answer
   x = 1,477.75